Slippery part of the elm (3)
I believe the answer is:
eel
'slippery part' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'of the elm' is the wordplay.
'of' indicates the answer is hidden within the clue.
'EEL' can be found hidden inside 'the elm'.
Can you help me to learn more?
(Other definitions for eel that I've seen before include "Almost scaleless fish" , "Slippery person" , "elusive person" , "Slippery creature" , "Serpentine fish" .)